Raspberry Pi 5 Speculation

Retro

I've just been thinking about the next step for the Raspberry Pi. Given the CPUs that Pis use are a few years behind the mainstream, what sort of CPU should we be expecting, and will it be the first step to emulating the PS2 and Gamecube (and the Xbox, if the Xbox allows it)?

mitu

At this stage, speculations are a bit far fetched - I don't think a Pi5 is in the works.

Given the CPUs that Pis use are a few years behind the mainstream

Which are the 'mainstream' CPUs at this point ?

PS2 and Gamecube (and the Xbox, if the Xbox allows it)?

There's no PS2 or Xbox emulators that run on an ARM CPU AFAIK, so that's a bit out of reach for a non-x86 SBC.

Retro

Which are the 'mainstream' CPUs at this point ?

I guess by 'mainstream' I mean whatever ARM chips are used in 2020 smartphones and tablets.

There's no PS2 or Xbox emulators that run on an ARM CPU AFAIK, so that's a bit out of reach for a non-x86 SBC.

One dude I'm subscribed to, ETA Prime, does videos of emulation on a range of devices. This is just an example, but the Samsung Galaxy Tab S7+ has a Qualcomm Snapdragon 865+ that incorporates three ARM Cortex-A77 & four ARM Cortex-A55, with the 'Prime Core' being clocked at 3.1Ghz. The following video features examples of PS2 and Gamecube emulation:

mitu

Damon PS2 is a hack job, their 'developers' tried recently to trademark the names for PPSSPP, RetroArch, Citra, RetroArch (and probably others) in mainland China and they've been using the PCSX2 source without releasing their modifications for years.

Samsung Galaxy Tab S7+ has a Qualcomm Snapdragon 865+ that incorporates three ARM Cortex-A77 & four ARM Cortex-A55, with the 'Prime Core' being clocked at 3.1Ghz

That's a nice system, though you could get a PC at that price point. It's true, probably not in in that mobile factor.

George Spiggott

@retro The first steps to Gamecube emulation are already being made on the Pi4. There are a couple of games (literally two so far that I know of) that run at a reasonable speed on 64 bit operating systems.

PS2 has nothing for the Pi but there is Play! an ARM based emulator that has a libretro core for Android. Having tried to run it on my mid range phone (Samsung S6) I imagine it will not run anything at any useful speed on a Pi.

I've been looking into Xbox emulation just today. I can't even find an X86 emulator with any kind of community support.

Retro

@mitu said in Raspberry Pi 5 Speculation:

Damon PS2 is a hack job, their 'developers' tried recently to trademark the names for PPSSPP, RetroArch, Citra, RetroArch (and probably others) in mainland China and they've been using the PCSX2 source without releasing their modifications for years.

Damn, just looked into them. Closed-source, Chinese-owned, DRM, requiring access to information on the device not related to emulation (checking SoC thermals and contacts, for example) and aforementioned code stealing - it's not recommended for use by an emulation wiki: https://emulation.gametechwiki.com/index.php/DamonPS2

@george-spiggott said in Raspberry Pi 5 Speculation:

@retro The first steps to Gamecube emulation are already being made on the Pi4. There are a couple of games (literally two so far that I know of) that run at a reasonable speed on 64 bit operating systems.

That's awesome, is there a thread on here for that?

PS2 has nothing for the Pi but there is Play! an ARM based emulator that has a libretro core for Android. Having tried to run it on my mid range phone (Samsung S6) I imagine it will not run anything at any useful speed on a Pi.

Yeah, just found an emulation wiki with useful information on different emulators for different consoles. Aside from the questionable DamonPS2 emulator, Play! is the only other emulator for mobile/arm.

I've been looking into Xbox emulation just today. I can't even find an X86 emulator with any kind of community support.

The Xbox is one of the hardest systems to emulate. In fact, it's only in the last few years that actual progress has been made. There are currently two x86 Xbox emulators in active development:

https://emulation.gametechwiki.com/index.php/Cxbx-Reloaded
https://emulation.gametechwiki.com/index.php/Xemu

Darksavior

A future pi might use the cortex A72 at its maximum speed of 2.5Ghz. That might be enough for full-speed cave shooters on mame2016 and maybe saturn with yabasanshiro or yabause. Might be able to handle beetle-psx too.

Not really interested in later gen consoles on the pi.

showstopper

The point of the pi is a cheap board with lots of scope to do things with. Don't expect a "high-end" CPU in a Pi.

George Spiggott

@Retro Yes, right here https://retropie.org.uk/forum/topic/28459/latest-gamecube-developments-on-pi4

** Wild speculation mode on **

Even without expecting cutting edge it would be reasonable to expect any future Pis to roughly follow the advancement of ARM chips. Since a new ARM SoC drops every year or so I would think it reasonable for a 'Pi 5' to follow that pattern. So currently we would be looking at maybe an A75 core if next year was a release date (currently there is no reason to think this is the case). I think that two monitors at 4k 60Hz will be a goal for this future Pi and that increaced power may have side benefits for emulation. Personally I would prefer to see an emphasis on backward compatability over raw power as we have not yet seen the full potential of the Pi4 in this area. In terms of ports I would like to see the Pi4 compute module's PCIe socket replace the USB3 sockets as that would be more versatile, possibly cheaper, and have a smaller form factor.

A major hardware revison so close to the 64 bit OS, graphics and audio drivers being finalised for the Pi4 (currently all have upgrades in beta or are still in beta) could be quite disruptive for the community so I think late 2021 to mid 2022 would be the earliest options for release dates for a 'Pi 5', although I think an A72 based 'Pi4B+' will be the next release, perhaps a little sooner than this. I imagine it would take advantage of the new SoC's improved thermals to lower the operating temperature, boost the clock speed slightly or maybe both. The afore mentioned replacement of the USB3 ports with a PCIe socket could also be an addition. It is possible that the number of RAM options and price points may change.

Brunnis

@mitu said in Raspberry Pi 5 Speculation:

I don't think a Pi5 is in the works.

Given the timelines involved with designing and validating new hardware, especially when it involves chip design, we can be very certain that Pi 5 development is quite far along already. I know a Pi employee (jamesh, on the forums) mentioned already ~1 year before the Pi 4 was released that they had a good understanding of what the Pi 5 would be. I'd guess that at this point we're at most ~1.5 years from a Pi 5 release. I would hope to see it already this coming summer, but that may be a bit too optimistic.

Of course, the Pi 4 has still not peaked, since we're still waiting for Pi OS 64-bit, the full KMS video driver and Vulkan support. Personally, though, I believe the Pi 5 will in large part compatible with all the SW development work that's going on now, i.e. they will most likely keep the GPU very similar (at least from an architectural perspective).

It's pretty hard to speculate about what the Pi 5 will look like, but I mostly agree with @george-spiggott. Regarding using A75 cores, power consumption of the Pi 4 is already pretty much at the limit for what's practical when it comes to passive cooling. It's unlikely that they'd increase it further. This makes it challenging to provide a generational performance leap without going down to more dense manufacturing processes (such as 20nm or 16nm). So, I'd expect a process upgrade for the Pi 5. I also believe that at 16nm (and maybe also 20nm?) they will need to make some provisions to be able to keep the 3.3V I/O on the 40-pin header, since the silicon is not 3.3V tolerant. This will add cost and complexity.

My hope for the next Pi is that they're able to alleviate some bottlenecks in the design. It seems like memory bandwidth is lower than it should be, possibly because of internal bus limitations. My guess is that this is one of the reasons the performance of N64 emulation is still quite bad, despite seemingly not being particularly CPU or GPU limited on the Pi 4.